Design Case Study: The Microsoft Arc Touch Mouse

The Microsoft Arc Touch Mouse has netted no less than two big design awards in the last year: a 2011 Red Dot Best of the Best,  and a 2011 IDEA Gold award. As a successor to Microsoft’s first generation (folding) Arc Mouse, this exceptional mobile computing device takes portability one step further: instead of folding, the arced mouse body flattens to a 15 mm thick slab. The integrated wireless transmitter activates when the form is popped up, then turns off when the mouse is flattened. One simple movement is all that is required to switch from arced form to flat.

Not only does the entire mouse body change shape, but the scroll wheel has been replaced with a haptic-enabled touch strip, which gives the user a familiar detented scrolling experience in a smaller package with less moving parts.

As with the first generation Arc Mouse, Microsoft partnered with San Francisco-based design studio One & Co to produce this elegant design. As a compliment to the Arc Keyboard, this mouse targets the mobile user who is looking for a product that is sophisticated yet still easy to use. Industrial designer Donn Koh takes us behind the scenes during the design process.

The biggest design challenge was clear: a mouse form that was substantial enough to provide an ergonomically satisfying mousing experience, but could be easily collapsed into a more portable package. The design team explored a variety of quick mock-ups to demonstrate possible arc-to-flat transition techniques.

More ideas were explored in a sketch phase, some based on physical mock-ups, some entirely new. Sketching allowed for some experimentation of the aesthetics of different shapes. An early source of inspiration was the concept of a bimetallic strip: often used in temperature gauges, two different metallic materials bonded together will bend repeatably in one direction when exposed to heat. This is due to the two materials having different coefficients of thermal expansion.

Expanding on this idea, two flat flexible strips bonded at one end will slide over each other when subjected to a bend. This bent form can be held in the shape of an arc with a simple detent bump on the lower strip.

A simple breadboard was constructed to demonstrate the action, and became the basis for engineering development of the mouse.

Microsoft continued to evolve the design as the development progressed from concept to prototype to production. The snap lock was changed to a magnet, and a deceivingly complex mechanism was packaged into the tail of the mouse. Over 90 parts contribute to the operation, appearance, feel, and sound of the shapeshifting mechanism. Only 5mm thick, each part serves a specific purpose, and is design to last at least 40,000 cycles.

The project took hundreds of hours to design and build. A few of the folks involved in the project were:

Cory Worth – One & Co.
Jonah Becker – One & Co.
Donn Koh – One & Co.
Scott Croyle – One & Co.
Young Kim – Microsoft
Monique Chatterjee – Microsoft
Dave Zucker – Microsoft